Numerous processes and systems have been provided for the thermal treatment of organic substances and, especially, for the thermal conversion of organic wastes into useful products by a process involving dehydration, roasting or baking and sterilization.
For example, sludges obtained from municipal sewage treatment are commonly dewatered and subjected to some type of sterilization treatment involving heating if the organic matter is to be used subsequently, e.g. in soil enrichment. The organic material may thus be roasted and a variety of plants have been provided for this purpose.
Similar systems are used for the thermal treatments of other organic wastes and materials.
One of the disadvantages of conventional systems is the evolution of vapors and gases which carry with them odorific components and frequently even toxic substances which should not be discharged into the atmosphere. The conventional systems also have the disadvantage that they are generally complex, require much manpower and are thermally uneconomical.